1. Field of the Invention
The present invention relates to an apparatus for cutting corners of a sheet discharged from an image formation apparatus such as a copier and various types of printers in an inclined or curved manner, or concurrently therewith, punching a punch hole in the sheet, and more particularly, to a corner cut apparatus for cutting corners of a transported sheet in an inclined or curved manner, corner cut•punch apparatus further provided with a punch mechanism for punching a punch hole in addition thereto, an image formation apparatus provided with the apparatus, and a sheet corner cut•punch method.
2. Description of the Related Art
In recent years, it has been known widely that predetermined sheet processing is performed on a sheet carried out of an image formation apparatus. Ina sheet processing apparatus coupled to an image formation apparatus, the apparatus is also provided which performs punch blade processing and binding processing.
In addition, since corners of a sheet tend to bend, it is known that the appearance of a sheet shape is improved to add a tender sense by cutting corners on the lead edge or cutting corners of the sheet.
For example, in Japanese Patent Gazette No. 3627073 is shown an apparatus where a sheet is nipped between a shifting arc-shaped cut blade and a receiving blade that receives the cut blade, and the cut blade is manually pressed into the receiving blade toward corners of the sheet to cut the corners of the sheet.
Further, in Japanese Patent Application Publication No. H06-156817 is disclosed an apparatus that is a paper feed apparatus which cuts both corners on the lead edge side of a sheet transported from a sheet storage section that stacks sheets in an inclined or curved manner with a sheet cut mechanism, then feeds the sheet to an image formation apparatus, and thereby reduces a paper jam caused by corner bending of the sheet.
Furthermore, in Japanese Patent Application Publication No. 2015-189551 is disclosed an apparatus targeted for sheets in the shape of a bunch where a cut blade longer than a width of a transported sheet and a punching blade are provided in a single unit, punching is first performed, and subsequently, cutting is performed.
However, the apparatus shown in above-mentioned Japanese Patent Gazette No. 3627073 is to manually cut corners of a sheet, requires a time for cutting, while manually setting a cut range, and therefore, is not stable.
On the other hand, in the apparatus shown in Japanese Patent Application Publication No. H06-156817, it is possible to automatically cut corners of a sheet, but only the lead edge side of the sheet is cut, and it is not possible to cut the end edge side of the sheet. In the case of cutting the sheet end edge, it is considered changing directions of the cut blade and the unit of the cut blade, and it is necessary to use a cut-blade direction changing mechanism.
Further, in the apparatus shown in Japanese Patent Application Publication No. 2015-189551, the cut blade is not capable of cutting corner cuts of the sheet in an inclined or curved manner, and further, since the cut blade is comprised of a blade that is longer than the width of the sheet and that is relatively heavy, it is difficult to downsize the drive and the entire apparatus.
The present invention was made in view of the above-mentioned problems, and it is a first object of the invention to provide a corner cut apparatus which enters in a direction crossing a transport path of a sheet to cut corners at the lead edge and end edge of a transported sheet in an inclined or curved manner. Further, it is a second object to provide a corner cut•punch apparatus by providing the apparatus with a punch blade to also enable a hole to be punched.